Theoretical studies of the ignition and combustion of silane-hydrogen-air mixtures

A chemical kinetic mechanism is proposed for the combustion of silane-hydrogen-oxygen-nitrogen mixtures in the initial temperature range from 800K to 1250K and pressure range from 0.5 to 1.35 atm. The mechanism yields results which are in agreement with published ignition delay times obtained from shock tube experiments. Comparisons between the results obtained using the proposed mechanism and that of an alternative mechanism reveal that the former predicts appreciably shorter ignition delay times, but a flame blowout envelope which is shifted so as to decrease the stable flame region. Over much of the thermodynamic range examined, the mechanism predicts long reaction times. A three step global mechanism is proposed which closely models the ignition phase of SiH4 - H2 - air combustion; however, the reaction phase is less well reproduced by the global model. The necessity for additional experimental data to further assess the proposed models is stressed

„Jak stać się lustrem tej nowoczesności?” Planetarność, periodyzacja i nowe studia modernistyczne

The main task of this article is to enter into discussion with a concept of modernism as an expressive dimension of modernity by Susan Stanford Friedman. In place of statements of epistemological nature, the author of the article proposes ontological questions and return to such an understanding of modernism which would primarily stress a specific Anglo-Saxon modernity. This kind of a historically motivated definition should protect the coherence of modernism as a research subject.The main task of this article is to enter into discussion with a concept of modernism as an expressive dimension of modernity by Susan Stanford Friedman. In place of statements of epistemological nature, the author of the article proposes ontological questions and return to an understanding of modernism which would primarily stress a specific historical, global modernity. This kind of a historically motivated definition should protect the coherence of modernism as a research subject

A comprehensive model to determine the effects of temperature and species fluctuations on reaction rates in turbulent reacting flows

Reaction rates in turbulent, reacting flows are reviewed. Assumed probability density functions (pdf) modeling of reaction rates is being investigated in relation to a three variable pdf employing a 'most likely pdf' model. Chemical kinetic mechanisms treating hydrogen air combustion is studied. Perfectly stirred reactor modeling of flame stabilizing recirculation regions was used to investigate the stable flame regions for silane, hydrogen, methane, and propane, and for certain mixtures thereof. It is concluded that in general, silane can be counted upon to stabilize flames only when the overall fuel air ratio is close to or greater than unity. For lean flames, silane may tend to destabilize the flame. Other factors favoring stable flames are high initial reactant temperatures and system pressure

Nonlinear combustion instability in liquid-propellant rocket motors Final report

Mathematical models of nonlinear combustion instabilities in liquid propellant rocket engin

Nonlinear combustion instability in liquid-propellant rocket motors Quarterly report

Fluid dynamic pancake model and droplet evaporation and combustion analysis related to nonlinear combustion instability in liquid propellant rocket motor

Metadata Schema for Modernist Networks

Loyola University Chicago will host a workshop for 16 participants in digital modernist projects in the U.S., Canada, and abroad which will result in the launching of ModNets as the most recent "node" in the Advanced Research Consortium (ARC). ModNets, a federation of digital projects in the field of modernist studies, faces unique challenges as it joins the ARC organization: we will address issues specific to the field of modernist studies, particularly the metadata needs for new media, such as film and phonography. The purpose of this workshop, which will include project directors, ModNets and ARC leaders, and metadata analysts, is to review ARC's RDF (metadata) vocabulary in the light of modernist scholarship and enhance it to meet the particular needs of modernist artifacts. The outcome will be a list of proposed changes to the existing ARC vocabularies and a working set of RDF documents for two existing projects

A comprehensive model to determine the effects of temperature and species fluctuations on reaction rates in turbulent reacting flows

The use of probability theory to determine the effects of turbulent fluctuations on reaction rates in turbulent combustion systems is briefly reviewed. Results are presented for the effect of species fluctuations in particular. It is found that turbulent fluctuations of species act to reduce the reaction rates, in contrast with the temperature fluctuations previously determined to increase Arrhenius reaction rate constants. For the temperature fluctuations, a criterion is set forth for determining if, in a given region of a turbulent flow field, the temperature can be expected to exhibit ramp like fluctuations. Using the above results, along with results previously obtained, a model is described for testing the effects of turbulent fluctuations of temperature and species on reaction rates in computer programs dealing with turbulent reacting flows. An alternative model which employs three variable probability density functions (temperature and two species) and is currently being formulated is discussed as well

Daughters\u27 Perspectives on Maternal Substance Abuse: Pledge to Be a Different Kind of Mother

The purpose of this grounded theory (Strauss & Corbin, 1998) study was to explore the experiences of racially and culturally diverse young mothers whose own mothers abused substances two decades ago when substance abuse peaked in inner city, urban neighborhoods in the United States and to identify the factors that have influenced how they parent their own children today. Semi-structured interviews were conducted with ten drug-free mothers who report having been raised by a mother who was addicted to drugs, primarily crack cocaine during their childhoods. The emergent grounded theory is that exposure to maternal substance abuse has a significant and unique impact on female children throughout their lifespan, with particular emphasis at the onset of motherhood. Among the goals the young mothers expressed is that they wanted to be there for their children, protect their daughters from sexual abuse, and raise sons who do not abuse women

Coulomb Distortion Effects for (e,e'p) Reactions at High Electron Energy

We report a significant improvement of an approximate method of including electron Coulomb distortion in electron induced reactions at momentum transfers greater than the inverse of the size of the target nucleus. In particular, we have found a new parametrization for the elastic electron scattering phase shifts that works well at all electron energies greater than 300 $MeV$. As an illustration, we apply the improved approximation to the $(e,e'p)$ reaction from medium and heavy nuclei. We use a relativistic ``single particle'' model for $(e,e'p)$ as as applied to $^{208}Pb(e,e'p)$ and to recently measured data at CEBAF on $^{16}O(e,e'p)$ to investigate Coulomb distortion effects while examining the physics of the reaction.Comment: 14 pages, 3 figures, PRC submitte

Urban Multifunctional Land Use: Theoretical and Empirical Insights on Economies of Scale, Scope and Diversity

A recent planning device aimed at dealing with land scarcity is the propagation of multifunctional land use. This paper describes the evolution of urban planning concepts and their links to economic theory. We argue that the most distinctive feature of multifunctional land use is its emphasis on return to diversity. This concept is rooted in the modern economic theory of agglomeration. Empirical evidence is shown to provide some support for the quantitative relevance of return to diversity, but is still to a large extent in its infancy. More evidence is required for policy purposes aimed at identifying the optimal extent to which multifunctional land use projects have to be pursued